Active Transmembrane Water Cycling For Neuronal Activity Detection

Neurons absorb and release water when they relay messages throughout the brain, according to a study by researchers at the National Institutes of Health and other institutions. Tracking this water movement with imaging technology may one day provide valuable information on normal brain activity, as well as how injury or disease affect brain function.

Neurons communicate with each other by a process known as firing. In this process, they emit a slight electrical charge as an enzyme moves positively charged molecules — potassium and sodium ions — through the cell membrane.

In the current study, when researchers stimulated cell cultures of rat neurons to fire, they found that the exchanges of potassium and sodium ions was accompanied by an increase in the number of water molecules moving into and out of the cell.

Neuronal Firing

The researchers, led by Peter Basser, Ph.D., noted that their method works only in cultures of neurons and additional studies are necessary to advance the technology so that it can be used to monitor neuronal firing in living organisms.

Basser is Senior Investigator, Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health.

Funding for the work came from the Intramural Research Program (IRP) of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institute of Mental Health, Fundamental Research Funds for Central Universitie, Zhejiang University, and the OHSU Advanced Imaging Research Center.